text: #include <stdlib.h>
  #include <stdint.h>
  
  #include "nlr.h"
  #include "misc.h"
  #include "mpconfig.h"
  #include "obj.h"
  
  /******************************************************************************/
  /* range                                                                      */
  
  typedef struct _mp_obj_range_t {
      mp_obj_base_t base;
      // TODO make these values generic objects or something
      machine_int_t start;
      machine_int_t stop;
      machine_int_t step;
  } mp_obj_range_t;
  
  mp_obj_t range_getiter(mp_obj_t o_in) {
      mp_obj_range_t *o = o_in;
      return mp_obj_new_range_iterator(o->start, o->stop, o->step);
  }
  
  static const mp_obj_type_t range_type = {
      { &mp_const_type} ,
      "range",
      NULL, // print
      NULL, // call_n
      NULL, // unary_op
      NULL, // binary_op
      range_getiter,
      NULL, // iternext
      {{NULL, NULL},}, // method list
  };
  
  // range is a class and instances are immutable sequence objects
  mp_obj_t mp_obj_new_range(int start, int stop, int step) {
      mp_obj_range_t *o = m_new_obj(mp_obj_range_t);
      o->base.type = &range_type;
      o->start = start;
      o->stop = stop;
      o->step = step;
      return o;
  }
  
  /******************************************************************************/
  /* range iterator                                                             */
  
  typedef struct _mp_obj_range_it_t {
      mp_obj_base_t base;
      // TODO make these values generic objects or something
      machine_int_t cur;
      machine_int_t stop;
      machine_int_t step;
  } mp_obj_range_it_t;
  
  mp_obj_t range_it_iternext(mp_obj_t o_in) {
      mp_obj_range_it_t *o = o_in;
      if ((o->step > 0 && o->cur < o->stop) || (o->step < 0 && o->cur > o->stop)) {
          mp_obj_t o_out = MP_OBJ_NEW_SMALL_INT(o->cur);
          o->cur += o->step;
          return o_out;
      } else {
          return mp_const_stop_iteration;
      }
  }
  
  static const mp_obj_type_t range_it_type = {
      { &mp_const_type },
      "range_iterator",
      NULL, // print
      NULL, // call_n
      NULL, // unary_op
      NULL, // binary_op
      NULL, // getiter
      range_it_iternext,
      {{NULL, NULL},}, // method list
  };
  
  mp_obj_t mp_obj_new_range_iterator(int cur, int stop, int step) {
      mp_obj_range_it_t *o = m_new_obj(mp_obj_range_it_t);
      o->base.type = &range_it_type;
      o->cur = cur;
      o->stop = stop;
      o->step = step;
      return o;
  }
  